1. Field of the Invention
The present invention generally relates to a fuel injected internal combustion engine. More specifically, the present invention relates to a fuel injected internal combustion engine with direct fuel injection into the combustion chamber and spark-ignition.
2. Background Information
An example of a fuel injected internal combustion engine with direct fuel injection into the combustion chamber and spark-ignition is disclosed in Japanese Laid-Open Patent Publication No. 11-82028. In this publication, a fuel injection valve is arranged in an upper part of a combustion chamber and a cavity is formed in the top of the piston. The fuel injection valve injects a fuel stream generally shaped as a hollow circular cone toward the cavity of the piston and a spark plug ignites the fuel-air mixture formed by the injected fuel.
The cavity has a generally cylindrical surrounding wall surface, a bottom surface that connects smoothly with the surrounding wall surface, and a central protrusion that is shaped generally like a circular cone and connects smoothly with the bottom surface. The bulk of the generally hollow circular cone shaped fuel stream injected toward the cavity strikes the surrounding wall, proceeds along the bottom surface, and rises upward while following the contour of the protrusion and converging toward the center. As a result, the fuel-air mixture is formed that is concentrated in the area surrounding the spark plug, which is positioned directly above the protrusion. This arrangement allows excellent laminar combustion to be achieved.
The so-called swirl injection valve is sometimes used to inject fuel in such a manner that the fuel stream has the shape of a circular cylinder. The swirl injection valve injects the fuel while imparting a rotating component to the fuel flow inside the injection vent. The rotating component rotates about the axis of the injection vent.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved direct fuel injection engine. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.